17alpha-alkanoyloxy-6alpha-methyl-3beta-trialkyl-siloxypregn-4-en-20-ones

ABSTRACT

Preparation and the selective pepsin-inhibiting and progestational activity of 17 Alpha -alkanoyloxy-6 Alpha methyl-3 Beta -trialkylsiloxypregn-4-en-20-ones are disclosed.

Umled States Patent [1 1 [1.11 3,869,481 Sollman I Mar. 4, 1975 l7ALPHA-ALKANOYLOXY-GALPHA METHYL-3BETA-TRIALKYL-SILOXY- [56] References Cited PREGN'4'EN'2O'ONES UNITED STATES PATENTS Invent Paul Sollman, Wilmette 3,126,399 3/1964 Sollman zoo/397.4 Assignee: G. D. Seafle & Co. Chicago, L 3,671,555 6/1972 Teichmuller CI ill 260/3974 [22] Filed: 1973 Primary Examiner-Elbert L. Roberts [21] A l N 418,458 Attorney, Agent, or FirmJ0hn M. Brown Related US. Application Data [63] Continuation-impart of Ser. No. 181,230, Sept. l6 [57] ABSTRACT I971 abandoned. Preparation and the selective pepsin-inhibiting and progestational activity. of 17a-alkan0yloxy-6a-methyl- U.S. Cl. J 3B-trialkylsfloxypregn 4-en-2()-one5 are disclosed [51] Int. Cl. C07c 169/32 581 Field of Search 260/3974 3 Clam, N0 Drawmgs 17ALPHA-ALKANOYLOXY-6ALPHA-METHYL- 3BETA-TRIALKYL-SIL0XYPREGN-4-EN 20 ONES This application is a continuation-in-part of my copending application Ser. No, 181,230filedSept. 16, I97 I now abandoned.

This invention relates to l7a-alkanoyloxy-6amethyl-3B-trialkylsiloxypregn-4-en-20-ones. More particularly, this invention provides new, useful and unobvious chemical compounds having the formula Among the alkyls called for by the foregoing formula, lower alkyls are preferred, which is to say methyl, ethyl,

propyl, isopropyl, butyl, isobutyl, sec.-butyl, tert.-butyl',

pentyl, neopentyl, hexyl, isohexyl, and like monovalent, saturated, acyclic, straightor branched-chain, hydrocarbon radicals of empirical formula wherein n represents a positive integer less than 8. Whether these radicals are the same, or different, in the enformulated compounds is not critical for the purposes hereof.

The compounds of this invention are useful by reason of their valuable and selective biological properties. Thus, for, example, they are progestational and pepsininhibiting, but not estrogenic.

The progestational utility of the instant compounds is evident from results of the following standardized test, which is a modification of the well-known procedure described by Clauberg in. C. Zentr. Gynakoh, 54, 2757 (1930): To each of a group of 3-4 immature, female rabbits weighing about 1 kg. and primed with l7B-estradiol by subcutaneously injecting ug. thereof per animal on each of six successive days, test compound dissolved or suspended in corn oil issubcutaneously administered on each of five successive days beginning the next day after the last priming injection. Commonly, the initial daily dosage is 1 mg. of compound in 0.1 ml. of corn oil. other animals likewise ad ministered corn oil alone serve as controls. On the sixth day after the last priming injection, the animals are sacrificed; and a segment of each uterus is taken for histological examination whereby the degree of arborization of the endometrial glands is graded in accordance with a method similar to that described by McPhail in J. PhysioL, 83, 145 (1934). A +1 response represents the effect of estrogen priming alone and is indicated by the absence ofglandular proliferation. A +2 response is induced in the estrogen-primed animals by approximately 0.05 mg. of progesterone administered subcutaneously, and is considered to represent minimal progestational activity. Responses in the range +3 to +4 reflect potent progestational effects typical of those produced by larger doses (-0.l mg.) of subcutaneously administered progesterone. If the average rating for the test animals is less than +2 at the 1 mg. dose level, the compound is considered inactive. If the average rating at this dose is greater than +2, the test is repeated with compound administered in amounts decreased according to the progression 05, 0.2, 0,], 0.05, 0.02, 0.01 mg. until a dose insufficient to produce an average response of+2 can be determined. Potency ofthe compound in per cent, relative to progesterone, is then calculated by dividing the next higher dose into 0.05 and multiplying by 100. A preferred embodiment ofthis invention, l7a-acetoxy-6a-methyl-3,B=trimethylsiloxypregn-4-en-20-one, was found active in this test, its potency ranging from 1 to 5 times that of progesterone The pepsin-inhibiting utility of the instant compounds is evident from results of the standardized test for this property described in US. Pat. No. 3,475,420. In that test, l7a-acetoxy-6a-methyl-3B- trimethylsiloxypregn-4-en-20-one was found to produce a 10 percent inhibition of the proteolysis of hemoglobin by pepsin.

The aforesaid biological activities are the more interesting because l7a-acetoxy-3B-hydroxy-(m-methylpregn-4-en-20-one, which is presumably typical of a group of compounds claimed in US. Pat. No. 3,126,399 all distinguished from the compounds of this invention by the absence of a 3-trialkylsilyl grouping, was found 25 times as potent as progesterone but devoid of pepsin-inhibiting activity in the tests referred to. Moreover, the specified prior art 38-01 was found to be a potent estrogen (effective subcutaneously at doses as low as lOugm.) in the standardized test for estrogeni'city described in US. Pat. No. 3,501,506, whereas l7a-acetoxy-6a-methyl-3B-trimethylsiloxypregn-4-en- 20-one was inactive in that test. Contrary, therefore, to what has sometimes been suggested, the biological effects of trialkylsilyl substitution are clearly not predictable. Further documentation of this unpredictability can be found in US. Pat. No. 3,560,532, where compounds of Formula II are distinguished from compounds of Formula [II as corticoid and progestational agents, respectively; yet certain compounds can be structurally represented by both formulas (when Z methylene, R and R methyl, R lower alkanoyloxy, R lower alkyl, R and Y hydrogen, and R oxo).

Those skilled in the art will recognize that observa tions of activity in standardized tests for particular biological effect are fundamental to the development of valuable new drugs, both veterinary and human.

Preparation of the instant compounds proceeds by contacting a compound of the formula with a chlorosilane of the formula in pyridine solution. Addition to the reaction mixture of the corresponding hexaalkyldisiilazane 3 (alkyl) SiNHSi( alkyl appears to enhance the yield.

The following examples describe in detail compounds illustrative of the present invention and methods which have been devised for their preparation. It will be apparent to those skilled in the art that many modifications, both of materials and of methods may be practiced without departing from the purpose and intent of this disclosure. Throughout the examples hereinafter set forth, temperatures ae given in degrees centigrade and relative amounts of materials in parts by weight, except as otherwise noted.

EXAMPLE 1 l7a-Acetoxy-6a-methyl-3B-trimethylsiloxypregn-4- en-ZO-one. To a solution of 3 parts of l7a-acetoxy-3B- hydroxy-6a-methylpregn-4-en-20-one in 30 parts of pyridine is added approximately 9 parts of hexamethyldisilazane, followed by approximately 3 parts of trimethylchlorosilane. The reactants are thoroughly mixed and then allowed to stand for minutes, whereupon 240 parts of pentane is introduced. The resultant mixture is washed with water, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is chromatographed on silica gel, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising 1 percent ethyl acetate in benzene, on evaporation of solvent and recrystallization of the residue from pentane, l7a-acetoxy-6a-methyl-3B- trimethylsiloxypregn-4-en-20-one melting at approximately 145 is obtained. The product has the formula EXAMPLE 2 l7a-Acetoxy-3B-ethylmethylpropylsiloxy-6amethylpregn-4-en-20-one. To a solution of 4 parts of l7a-acetoxy-3B-hydroxy-6a-methylpregn-4-en-20-one in 50 parts of pyridine is added, with vigorous stirring, 34 parts of ethylmethylpropylchlorosilane. Stirring is continued for 10 minutes, whereupon the reactants are diluted with 200 parts of pentane. The resultant mixture is washed with water, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is ethylmethylpropylsiloxy-6a-methylpregn-4-en-20-one, having the formula 'EXAMPLE 3 l7a-l-lexanoyloxy-6a-methyl-3B trimethylsiloxypregn-4-en-20-one. To a solution of 7 parts of 17ahexanoyloxy-3B-hydroxy-6a-methylpregn-4-en-20-one in parts of pyridine is added, with vigorous stirring,

35 parts of hexamethyldisilazane, followed by 20 parts of trimethylchlorosilane. Stirring is continued for approximately 5 minutes, whereupon the reactants are diluted with 250 parts of pentane. The resultant mixture is washed with water, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is l7a-hexanoyloxy-oa-methyl-3B- trimethylsiloxypregn-4-en-20-one, having the formula (CH3) aSi O EXAMPLE 4 hexanoyloxy-a-rnethylpregn-4-enfi-one, the formula of which is What is claimed is: 1. A compound of the formula (lower alkyl) SlO 2. A compound according to claim I having the formula 3. A compound according to claim 1 which is acctoxy-6a-methyI-3B-trimethylsilioxypregn-4-en- 20-one.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,869, i8l DATED Mar. i, 1975 |NVENTOR(S) 1 Paul B. Sollman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Columns l3, that portion of the formulas reading should read Column 3, line 10, "ae" should read are UNITED STATES IPATENT OFFICE CERTiFKCATE {I CQRR CTEGN' PATENT NO. 359,1481

' Li o !NVENTOR(S) Paul B. Sollman It is certified thai ror appevara in the above-identified patent and thai said Letters Patent are heieby cc-rre=:ed as shown beEow;

Column 4, that portion of the third formula reading 0 HO Lo 0 II N @ Clower alkyl should read c-.=o 0 H3O ll 0-C-lower alkyl Signed and Sealed this fourth D8) of November 1 975 [SEAL] Attest:

RUTH c. MASON c. MARSHALL DANN (ummissinner of Pa tents and Trademarks Arresting Officer 

1. A COMPOUND OF THE FORMULA
 2. A compound according to claim 1 having the formula
 3. A compound according to claim 1 which is 17 Alpha -acetoxy-6 Alpha -methyl-3 Beta -trimethylsiloxypregn-4-en-20-one. 